[core] Rewrite image handling

* Consolidate Image and StillImage
* Typecheck unassociated vs premultiplied images
* Rewrite default platform image decoding implementation

9 files changed, 38 insertions, 41 deletions

diff --git a/src/mbgl/map/map_context.cpp b/src/mbgl/map/map_context.cpp
index cf06dd06eb..f00b3eaf55 100644
--- a/src/mbgl/map/map_context.cpp
+++ b/src/mbgl/map/map_context.cpp
@@ -1,7 +1,6 @@
 #include <mbgl/map/map_context.hpp>
 #include <mbgl/map/map_data.hpp>
 #include <mbgl/map/view.hpp>
-#include <mbgl/map/still_image.hpp>
 
 #include <mbgl/platform/log.hpp>
 
@@ -200,22 +199,22 @@ void MapContext::renderStill(const TransformState& state, const FrameData& frame
     }
 
     if (data.mode != MapMode::Still) {
-        fn(std::make_exception_ptr(util::MisuseException("Map is not in still image render mode")), nullptr);
+        fn(std::make_exception_ptr(util::MisuseException("Map is not in still image render mode")), {});
         return;
     }
 
     if (callback) {
-        fn(std::make_exception_ptr(util::MisuseException("Map is currently rendering an image")), nullptr);
+        fn(std::make_exception_ptr(util::MisuseException("Map is currently rendering an image")), {});
         return;
     }
 
     if (!style) {
-        fn(std::make_exception_ptr(util::MisuseException("Map doesn't have a style")), nullptr);
+        fn(std::make_exception_ptr(util::MisuseException("Map doesn't have a style")), {});
         return;
     }
 
     if (style->getLastError()) {
-        fn(style->getLastError(), nullptr);
+        fn(style->getLastError(), {});
         return;
     }
 
@@ -246,7 +245,7 @@ bool MapContext::renderSync(const TransformState& state, const FrameData& frame)
     painter->render(*style, frame);
 
     if (data.mode == MapMode::Still) {
-        callback(nullptr, view.readStillImage());
+        callback(nullptr, std::move(view.readStillImage()));
         callback = nullptr;
     }
 
@@ -320,7 +319,7 @@ void MapContext::onResourceLoadingFailed(std::exception_ptr error) {
     assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
 
     if (data.mode == MapMode::Still && callback) {
-        callback(error, nullptr);
+        callback(error, {});
         callback = nullptr;
     }
 }
diff --git a/src/mbgl/map/view.cpp b/src/mbgl/map/view.cpp
index 5da290534a..fa8b7584cc 100644
--- a/src/mbgl/map/view.cpp
+++ b/src/mbgl/map/view.cpp
@@ -1,6 +1,5 @@
 #include <mbgl/map/view.hpp>
 #include <mbgl/map/map.hpp>
-#include <mbgl/map/still_image.hpp>
 
 #include <cassert>
 
@@ -11,8 +10,8 @@ void View::initialize(Map *map_) {
     map = map_;
 }
 
-std::unique_ptr<StillImage> View::readStillImage() {
-    return nullptr;
+UnassociatedImage View::readStillImage() {
+    return {};
 }
 
 void View::notifyMapChange(MapChange) {
diff --git a/src/mbgl/renderer/raster_bucket.cpp b/src/mbgl/renderer/raster_bucket.cpp
index 4a7dfeda05..37e5c31cc4 100644
--- a/src/mbgl/renderer/raster_bucket.cpp
+++ b/src/mbgl/renderer/raster_bucket.cpp
@@ -23,7 +23,7 @@ void RasterBucket::render(Painter& painter,
     painter.renderRaster(*this, dynamic_cast<const RasterLayer&>(layer), id, matrix);
 }
 
-bool RasterBucket::setImage(std::unique_ptr<util::Image> image) {
+bool RasterBucket::setImage(PremultipliedImage image) {
     return raster.load(std::move(image));
 }
 
diff --git a/src/mbgl/renderer/raster_bucket.hpp b/src/mbgl/renderer/raster_bucket.hpp
index 2882a94bbd..e12257d864 100644
--- a/src/mbgl/renderer/raster_bucket.hpp
+++ b/src/mbgl/renderer/raster_bucket.hpp
@@ -18,7 +18,7 @@ public:
     void render(Painter&, const StyleLayer&, const TileID&, const mat4&) override;
     bool hasData() const override;
 
-    bool setImage(std::unique_ptr<util::Image> image);
+    bool setImage(PremultipliedImage);
 
     void drawRaster(RasterShader& shader, StaticVertexBuffer &vertices, VertexArrayObject &array);
 
diff --git a/src/mbgl/sprite/sprite_parser.cpp b/src/mbgl/sprite/sprite_parser.cpp
index a8ed4f0e12..3b6464be9e 100644
--- a/src/mbgl/sprite/sprite_parser.cpp
+++ b/src/mbgl/sprite/sprite_parser.cpp
@@ -14,7 +14,7 @@
 
 namespace mbgl {
 
-SpriteImagePtr createSpriteImage(const util::Image& image,
+SpriteImagePtr createSpriteImage(const PremultipliedImage& image,
                                  const uint16_t srcX,
                                  const uint16_t srcY,
                                  const uint16_t srcWidth,
@@ -37,18 +37,18 @@ SpriteImagePtr createSpriteImage(const util::Image& image,
 
     std::string data(dstWidth * dstHeight * 4, '\0');
 
-    auto srcData = reinterpret_cast<const uint32_t*>(image.getData());
+    auto srcData = reinterpret_cast<const uint32_t*>(image.data.get());
     auto dstData = reinterpret_cast<uint32_t*>(const_cast<char*>(data.data()));
 
-    const int32_t maxX = std::min(image.getWidth(), uint32_t(srcWidth + srcX)) - srcX;
-    assert(maxX <= int32_t(image.getWidth()));
-    const int32_t maxY = std::min(image.getHeight(), uint32_t(srcHeight + srcY)) - srcY;
-    assert(maxY <= int32_t(image.getHeight()));
+    const int32_t maxX = std::min(uint32_t(image.width), uint32_t(srcWidth + srcX)) - srcX;
+    assert(maxX <= int32_t(image.width));
+    const int32_t maxY = std::min(uint32_t(image.height), uint32_t(srcHeight + srcY)) - srcY;
+    assert(maxY <= int32_t(image.height));
 
     // Copy from the source image into our individual sprite image
     for (uint16_t y = 0; y < maxY; ++y) {
         const auto dstRow = y * dstWidth;
-        const auto srcRow = (y + srcY) * image.getWidth() + srcX;
+        const auto srcRow = (y + srcY) * image.width + srcX;
         for (uint16_t x = 0; x < maxX; ++x) {
             dstData[dstRow + x] = srcData[srcRow + x];
         }
@@ -105,10 +105,11 @@ SpriteParseResult parseSprite(const std::string& image, const std::string& json)
     using namespace rapidjson;
 
     Sprites sprites;
+    PremultipliedImage raster;
 
-    // Parse the sprite image.
-    const util::Image raster(image);
-    if (!raster) {
+    try {
+        raster = decodeImage(image);
+    } catch (...) {
         return std::string("Could not parse sprite image");
     }
 
diff --git a/src/mbgl/sprite/sprite_parser.hpp b/src/mbgl/sprite/sprite_parser.hpp
index d385d77aea..468ba13c53 100644
--- a/src/mbgl/sprite/sprite_parser.hpp
+++ b/src/mbgl/sprite/sprite_parser.hpp
@@ -3,6 +3,7 @@
 
 #include <mapbox/variant.hpp>
 
+#include <mbgl/util/image.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/geo.hpp>
 
@@ -12,18 +13,12 @@
 
 namespace mbgl {
 
-namespace util {
-
-class Image;
-
-} // namespace util
-
 class SpriteImage;
 
 using SpriteImagePtr = std::shared_ptr<const SpriteImage>;
 
 // Extracts an individual image from a spritesheet from the given location.
-SpriteImagePtr createSpriteImage(const util::Image& image,
+SpriteImagePtr createSpriteImage(const PremultipliedImage&,
                                  uint16_t srcX,
                                  uint16_t srcY,
                                  uint16_t srcWidth,
diff --git a/src/mbgl/util/raster.cpp b/src/mbgl/util/raster.cpp
index 1c277040cd..c4d65ff320 100644
--- a/src/mbgl/util/raster.cpp
+++ b/src/mbgl/util/raster.cpp
@@ -25,13 +25,13 @@ bool Raster::isLoaded() const {
     return loaded;
 }
 
-bool Raster::load(std::unique_ptr<util::Image> image) {
+bool Raster::load(PremultipliedImage image) {
     img = std::move(image);
-    width = img->getWidth();
-    height = img->getHeight();
+    width = GLsizei(img.width);
+    height = GLsizei(img.height);
 
     std::lock_guard<std::mutex> lock(mtx);
-    if (img->getData()) {
+    if (img.data.get()) {
         loaded = true;
     }
     return loaded;
@@ -44,7 +44,7 @@ void Raster::bind(bool linear) {
         return;
     }
 
-    if (img && !textured) {
+    if (img.data && !textured) {
         upload();
     } else if (textured) {
         MBGL_CHECK_ERROR(glBindTexture(GL_TEXTURE_2D, texture));
@@ -59,7 +59,7 @@ void Raster::bind(bool linear) {
 }
 
 void Raster::upload() {
-    if (img && !textured) {
+    if (img.data && !textured) {
         texture = texturePool.getTextureID();
         MBGL_CHECK_ERROR(glBindTexture(GL_TEXTURE_2D, texture));
 #ifndef GL_ES_VERSION_2_0
@@ -67,8 +67,8 @@ void Raster::upload() {
 #endif
         MBGL_CHECK_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
         MBGL_CHECK_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
-        MBGL_CHECK_ERROR(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, img->getData()));
-        img.reset();
+        MBGL_CHECK_ERROR(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, img.data.get()));
+        img.data.reset();
         textured = true;
     }
 }
diff --git a/src/mbgl/util/raster.hpp b/src/mbgl/util/raster.hpp
index adf3b2cbf7..5c65c46e9d 100644
--- a/src/mbgl/util/raster.hpp
+++ b/src/mbgl/util/raster.hpp
@@ -20,7 +20,7 @@ public:
     ~Raster();
 
     // load image data
-    bool load(std::unique_ptr<util::Image> image);
+    bool load(PremultipliedImage);
 
     // bind current texture
     void bind(bool linear = false);
@@ -58,7 +58,7 @@ private:
     GLint filter = 0;
 
     // the raw pixels
-    std::unique_ptr<util::Image> img;
+    PremultipliedImage img;
 };
 
 }
diff --git a/src/mbgl/util/worker.cpp b/src/mbgl/util/worker.cpp
index 9940fb649c..00bdb5baee 100644
--- a/src/mbgl/util/worker.cpp
+++ b/src/mbgl/util/worker.cpp
@@ -17,8 +17,11 @@ public:
     void parseRasterTile(std::unique_ptr<RasterBucket> bucket,
                          const std::shared_ptr<const std::string> data,
                          std::function<void(RasterTileParseResult)> callback) {
-        std::unique_ptr<util::Image> image(new util::Image(*data));
-        if (!(*image)) {
+        PremultipliedImage image;
+
+        try {
+            image = decodeImage(*data);
+        } catch (...) {
             callback(RasterTileParseResult("error parsing raster image"));
         }